Coupling means for separable depth charge in ahead-thrown practice weapons



May 3 1955 l H. w. SEMON couPLINa-MEANS FOR SEPARABIEFDIRTH CHARGE 2707435 IN AHEAD-THROW PRACTICE WEAPONS Filed Nov. 21, 195o 'INIIINIIIUHTY m N o R fff|||||||||| s; i

'RMQRM ATTORNEYS CUPIZNG MEANS FR SEPARABLE DEPTH CHARGE EN AHEAD-TPRWN PRACTICE WEAPNS Howard W. Semen, Washington, D. C., and Richard A. Beasley, Cincinnati, Ohio Application November 2l, 1950, Serial No. 196,920

8 Claims. (Cl. 10Q-7) (Granted under Title 35, U. S. Code (1952), sec. 266) weapon is given here so that the relation of this Weapon a to the Burg weapon will be more readily understood. Primarily the weapon is a practice weapon used in simu lated warfare on submarines. ln training personnel tiring ahead-thrown weapons at such vessels, it is desirable and necessary to know how closely thereto the depth charge might normally explode so that data derived from such practice can be used to correct errors in subsequent irings. Since the prerequisite herein is practice, the weapon must not seriously damage the submarine, and the explosive components of the weapon must be as small as is consistent with producing a flash and a detonation of suicient intensities for detection abroad the target submarine.

Structurally the Weapon consists of a carrier and a core. The carrier is a standard weapon with the eX- plosive and fuzing components removed. The core is a small size depth charge possessing the things that the carrier lacks, namely the fuzing, arming and explosive components. The carrier is adapted to be directed toward the target so as to deliver the depth charge to the surface of the water, at which point the depth charge is automatically expelled from the carrier by hydrostatic action as brought out in the Burg application.

There are several ways in which the depth charge can be started on its trajectory. It may be launched by rocket or by dropping it from an airplane as in the Burg application, or by tiring the weapon from some type of mortar such as a spigot or Hedge-Hog projector. In the latter cases the accelerations are quite high, often on the order to 300 to 400 times the acceleration due to gravity. Such accelerations produce forces of 2400 to 3200 pounds on the back end of the depth charge. Such forces would severely damage the depth charge tins it the depth charge were carried as shown in the Burg application. ln addition such high accelerations, even it transmitted directly to the plastic tail cone of the depth charge of the Burg application, might produce compressive stresses which would cause the depth charge to rebound at the end of the acceleration with sufficient velocity to fly entirely free of the carrier. Since the depth charge would have a different trajectory in the air than the depth charge-carrier combination, it is important that they stay together until water impact.

The instant invention begins at this point, and the irnprovement on the Burg weapon lies rst, in the character of the coupling between the inner end of the depth charge and the bottom of the carrier well, secondly in the detent 2,77A35 Patented May 3, 1955 used in that coupling to prevent premature separation of the depth charge from the carrier.

The main object of the present invention is to provide a base assembly that will so cushion the launching shock transmitted to the depth charge tail cone as to reduce the tendency for elastic rebound suliiciently so that it will not pull the depth charge free of the retaining detent.

Another object of the invention is the provision of cushioning means between the depth charge and the carrier thereby to transmit the launching forces to the depth charge in such a way as to apply endwise thrust to the tail section thereof in a manner to avoid damage to the tail fins on the depth charge.

Another object of the invention is to make the foregoing cushioning means in the form of a lead plug that is deformed during launching in such a manner that the work done in shearing and extruding the lead greatly reduces the peak magnitudes of the setback forces applied to the depth charge and thereby reduces the elastic rebound of the depth charge to a point where it is no longer troublesome.

Other objects and many of the attendant advantages of the invention will be readily seen as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

Fig. l is a central, longitudinal section of an aheadthrown weapon such as herein contemplated, and

Fig. 2 is an enlarged sectional view of the base assembly, showing details of the detent and the lead plug cushioning system,

Following the pattern adopted above, the description is lrst directed to the practice weapon disclosed in the drawing which is somewhat similar to the Weapon of the Burg application. The explosively inert ahead-thrown weapon case 10 has combined with it an explosive depth charge lll. The ahead-thrown weapon case has a sleeve well 12 which is screwed in place in the thread course i3 1in lieu of the fuze well which otherwise would occupy this position. The inner end of the sleeve is bottomed by a washer 14.

The neck 1S into which the motor tube 16 is screwed is sealed oli. The compartment thus deiined inthe case 1G is filled with water 17 or an equivalent explosively inert material, to bring the weight and ilight characteristics of the weapon up to that of the service round. Three guide rods 18, l20 apart, support the depth charge in spaced relation to the inside wall of the sleeve well. The depth charge rides these rods and is guided thereby when driven out of the sleeve well by hydrostatic force.

In distinction from the Burg application, the motor tube contains a cartridge 19, the details of which are not important to this application. It is nested at the inner end of the motor tube next to the neck 15, and when the open end of said tube is tted onto the spigot of a Hedge-Hog projector and tired the weapon is projected under high acceleration. It is to cushion this acceleration so as to prevent the depth charge from rebounding from the carrier that the ductile plug arrangement was primarily devised.

The description is now directed to the latter plug arrangement, and in this arrangement the washer 14 is provided with a smooth central hole 22. This leads into a coaxial threaded hole Z3 of a boss 24, the ange 25 of which is welded onto the washer. A stem 26 is screwed into said hole. The purpose of the boss 24 is to supply thread depth since the washer is not thick enough to provide adequate support it the stem were screwed into it and not into the boss. The stern projects from a cup 28 which is the foundation of the base assembly now designated 29.

A cavity 30, which gives name to the cup, has a counterbore 31 which is threaded and forms a shoulder 32. rThe thimble 33 contains a lead plug 3S and the annulus 36 of a rearwardly slidable snap ring receptacle 37, that part of it adjacent to the annulus occupying the reduced passage 38 of the thimble. The thimble forms a shoulder 39 which is abutted by the annulus. A bevel 34 matches the pitch of the trailing edges of the ns 2l), avoiding damaging the latter at the end of setback from what would otherwise be the sharp edge of the thimble. When the thimble is screwed home, the transfer of pressure from the shoulder 39 of the annulus 36 presses the lead plug 3S tightly against the available part of the shoulder 32. The latter eventually becomes a shear edge.

The shear function occurs with the foregoing acceleration. The setback action forces the receptacle 37 to slide rearward to extrude the lead into the cavity 3b. The work done in forcing it past the shear edge 32 absorbs enough of the launching shock to largely eliminate the undesirable elastic rebound in the tail section d of the depth charge. ln installing the depth charge l1 in the sleeve l2 it is given a mild ramming action to engage a 'split snap ring di) with the receptacle 37. This, as shown, has a groove 42 to receive part of the ring. rfhe other part of the ring occupies the continuation of the groove, consisting of a space formed by a shouldered washer 43 that is held in place by the head of a screw 44. Said screw is driven into the tail section 45 of the depth charge. lt presses the washer d3 against a sleeve 46 which forms a spacer.

From this description the general arrangement and operation of the improved weapon should be apparent. The mode of putting the elements of the assembly together is clear from Figures l and 2. As has been brought out, the lead plug 35 is subject to compression and extrusion under setback force, thus absorbing much of the shock of accelerating the depth charge. The split ring d0 is the detent means, keeping the depth charge on its seat in the carrier case l@ during air transit. When the weapon strikes the water nose first, some of it enters the open end of the sleeve well l2 and, in accordance with the principle set forth in the Burg application, builds up a hydrostatic pressure in the bottom of the sleeve. Since this pressure is exerted in all directions, the snap ring 4l) soon yields to the pressure against the tail section 45. The depth charge is thus expelled automatically from the carrier and eventually explodes according to its set timing.

Obviously modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed is:

l. in a weapon comprising an explosively inert carrier having an open-ended recess, adapted to be projected under high acceleration, and an explosive depth charge having a tail section with tins, occupying said recess for expulsion at its open end; a base assembly constituting a coupling between said tail section and the bottom of the recess, said base assembly having embodied therein a hollow cylinder secured to the bottom of said recess and filled with a soft metallic material, said cylinder having a reduced orifice, means secured to said depth charge and engaging the metallic material, said means being movable in the cylinder by set-back force to cxtrude the metallic material through said orilice thereby to absorb the shock due to rebound of the depth charge in the carrier to avoid damage to the fins and subsequent premature separation of the depth charge from the carrier, and means for retaining the depth charge within said carrier during air transit of the weapon.

2. In a weapon comprising an explosively inert carrier having an open-ended recess, adapted to be projected under high acceleration, and an explosive depth charge having a tail section with tins, occupying said recess for expulsion at its open end; a coupling between said tail section and the bottom of the recess, said coupling consisting of an interconnected assembly of parts including a cylindrical member having communicating axially aligned large and small bores therein, a plunger slidably mounted in said large bore and movable in said large bore under action of set-back force incident to acceleration during launching of the weapon, a quantity of soft metallic material mounted in said large bore and engageable by said plunger during movement thereof for extrusion into the smaller bore thereby to absorb the shock due to rebound of the depth charge in the carrier to avoid damage to the tins and premature separation of the depth charge from the carrier, and a part for retaining the depth charge within said carrier during air transit of the weapon.

3. ln a weapon comprising an explosively inert carrier having an open-ended recess, adapted to be projected under high acceleration, and an explosive depth charge having a tail section with fins, occupying said recess for expulsion at its open end; a coupling between said tail section and the bottom of the recess, said coupling including an element displaceable by force of setback action initial to said acceleration, a cylindrical member having communicating axially aligned large and small bores therein, said displaceable element being slidably mounted in said large bore, a quantity of soft metallic material mounted in said large bore and engageable by said displaceable element for extrusion into the small bore by the displacement thereof to absorb the shock due to rebound of the depth charge in the carrier thereby to avoid damage to the ns and premature separation of the depth charge from the carrier.

4. in a weapon comprising an explosively inert carrier having an open-ended recess, adapted to be projected under high acceleration and an explosive depth charge having a tail section with tins, occupying said recess for expulsion at its open end; a coupling between said tail section and the bottom of the recess, said coupling including an element fixed in position adjacent to said bottom, said element having a cavity, an element displaceable in reference to said fixed element and its cavity, and a deformable element situated between the fixed and displaceable elements, being extrudable into the cavity by the displacement of said displaceable element to absorb the shock due to rebound of the depth charge in the carrier thereby to avoid damage to the ns and premature separation of the depth charge from the carrier.

5. In a weapon comprising an explosively inert carrier having an open-ended recess, adapted to be projected under high acceleration and an explosive depth charge having a tail section with tins, occupying said recess for expulsion at its open end; a cup fixed in position adjacent to the bottom of the recess, said cup having a shear edge, an element displaceable in reference to the cup and its shear edge, and a deformable element resting on the shear edge and being followed by the displaceable element, said deformable element being sheared across said edge and extruded into the cup by the setback action ou the displaceable element initial to said acceleration.

6. in a weapon comprising an explosively inert carrier having an open-ended recess, adapted to be projected under high acceleration and an explosive depth charge having a tail section with fins, occupying said recess for expulsion at its open end; a coupling between said tail section and the bottom of the recess, said coupling consisting of an interconnected assembly of parts including a cup affixed to the bottom of the recess, said cup having a shoulder, a thimble secured in the open end of the cup in abutment with part of the shoulder leaving an exposed shear edge, said thimble having a reduced passage delining a shoulder, a member slidably occupying the passage, having the depth charge attached thereto and having an annulus engaging the thimble shoulder, and a compression element resting between the shear edge and said member in readiness for extrusion into the cup on a setback action of said depth charge and its attached slidable member.

7. In a weapon comprising an explosively inert carrier having an open-ended recess therein for receiving an explosive depth charge having a tail section and comprising, in combination, a coupling for releasably securing the depth charge in said carrier, said coupling having a portion thereof fixed to the depth charge and a portion thereof fixed to the carrier, said portion fixed to the carrier having a recess and a movable member slideably mounted in said recess, said movable member having a socket therein, said recess having a reduced orice, a mass of extrudable metal mounted in said recess between said movable member and the reduced oriiice whereby the metal is extruded through the orilice as the movable member moves under influence of set-back force of the depth charge when the weapon is launched, said portion of the coupling fixed to the depth charge having a circumferential groove adjacent the end thereof, the end of the last-named portion being received in said socket in the movable member, a circumferential V-cut groove in said socket and in alignment with said first-named groove, and a spring locking ring in locking position in said V-cut groove and extending into said tirst named groove thereby to lock the depth charge in the carrier, said locking ring being forced into said rst-named groove to release the depth charge from the carrier when the carrier strikes the surface of a body of water.

8. In a weapon having an explosively inert carrier provided with an open-ended recess therein for receiving an explosive depth charge comprising, coupling means xed to said depth charge for releasably securing the depth charge within said recess and including a plunger movable under set-back force of the depth charge as the weapon is launched, a cylindrical member fixed to the bottom of said recess and having a large diameter bore, said large diameter bore receiving said plunger for movement therein, a quantity of soft metallic material lling the remainder of said large diameter bore, said bore having communicating therewith an axially aligned reduced bore, said metallic material being adapted to be extruded from the large diameter bore into the reduced bore as the plunger moves thereby to absorb the shock of setback on said depth charge during launching ofthe weapon.

References Cited in the tile of this patent UNITED STATES PATENTS 36,686 Callender Oct. 14, 1862 595,406 Porisse Dec. 14, 1897 1,275,686 Hill Aug. 13, 1918 1,569,545 Junghans Ian. 12, 1926 

